Researchers Hope Sharing Costs Will Spur Optical Chips

Combining electronic and optical components on silicon chips is a promising idea at an early stage, akin to the semiconductor industry 40 years ago. Researchers at the University of Washington, with help from Intel and others, plan to emulate a tactic that proved pivotal in keeping development going in those bygone days.

University of Washington College of Engineering

Optical chips are expected to pack many advances into a small space.

The goal of such new-wave chips is to send bits of data using tiny lasers rather than pulses of electricity–the technique used in long-haul communications–but at a fraction of the price. Trouble is, many of the people creating the most basic elements of such devices work at university labs, without access to expensive machines and materials needed to make prototypes.

When chip designers faced a similar situation, researchers Carver Mead and Lynn Conway helped lead the development in 1981 of MOSIS, the Metal Oxide Silicon Implementation Service. The idea of the organization, affiliated with a research unit of the University of Southern California, was to help overcome one obstacle–the cost of photomasks used in transferring chip designs onto silicon wafers.

One chip typically requires sets of such masks, which used to cost thousands of dollars and now can cost millions. The idea of MOSIS was to let university researchers share masks, with each assigned a portion of a chip to test their components rather than having to individually pay for a mask set for an entire chip. Once researchers pool their designs using this technique–called shuttle runs–they are sent to be fabricated by service manufacturers called foundries.

Now comes OpSIS, which stands for Optoelectronics Systems Integration in Silicon. The new center, announced Tuesday by the University of Washington, will offer shuttle runs for circuit designs in the infant field known as silicon photonics.

Michael Hochberg, an assistant professor of electrical engineering at the university involved in the effort, estimated the approach can bring a 100-fold reduction in costs. “We think it’s a big step forward for silicon photonics to have such a capability available to the academic community,” said Justin Rattner, Intel’s chief technology officer.

Intel, which has been working in silicon photonics for years, is donating about $250,000 to help the effort. Another backer is the U.S. Air Force Office of Scientific Research, which has been funding Hochberg’s work in the field.

One of the main reasons for military interest is radar, Hochberg says. Silicon photonics technology, if it can be perfected and the costs reduced as researchers hope, could be used either to make the largest radar systems much more powerful–or, just as important, could make today’s advanced radar systems small and light enough to be put on aircraft like unmanned drones, Hochberg says.

Another possibility relates to biomedical sensing devices; some that now cost hundreds of thousands of dollars and are the size of copy machines could one day be replaced with tiny optical chips that cost a dollar or less, Hochberg says.

The shared mask sets generated at OpSIS are expected to be turned into chips initially at a factory in Virginia operated by BAE Systems, a British defense contractor that has experience in silicon photonics. But other manufacturers will be invited to participate, with a preference for those with factories in the U.S.–an Air Force priority for components with defense applications.

“Everyone involved in this effort would like to see this happen in the United States,” Hochberg says.